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M Siddiqi

Publications and source records attributed to M Siddiqi.

At least 37 records · Page 2Linked to original sources
PubMed1988

The occurrence of preformed N-nitroso compounds in food samples from a high risk area of esophageal cancer in Kashmir, India.

Several commonly used raw foodstuffs from a high risk esophageal cancer region in Kashmir (India) were analysed for the presence of N-nitroso compounds. The food items were selected on the basis of their frequent consumption with particular emphasis on the preserved foods (dried, pickled and smoked) and those which are unique to the region. Nine out of 11 food items were found to contain low concentrations of N-nitrosodimethylamine (NDMA), N-nitrosopyrrolidine (NPYR), N-nitrososarcosine (NSAR), N-nitrosoproline (NPRO) and N-nitrosothaizolidine-4-carboxylic acid (NTCA). The preliminary survey shows a widespread contamination of N-nitroso compounds in raw foodstuffs from Kashmir.

Esophageal Neoplasms↗
PubMed1988

Formation of N-nitroso compounds under simulated gastric conditions from Kashmir foodstuffs.

Several foodstuffs and teas from an area of high esophageal cancer risk in Kashmir (India) were studied under simulated gastric conditions with a realistic nitrite concentration for the formation of N-nitroso compounds. N-Nitrosodimethylamine (NDMA), N-nitrosoproline (NPRO), N-nitrosothiazolidine-4-carboxylic acid (NTCA) and N-nitrosopipecolic acid (NPIC) were the main products in different foods. Significant amounts of NDMA were formed from dried fish (20 micrograms/kg), dried and pickled vegetables (35.6 micrograms/kg and 7.3 micrograms/kg), locally grown Brassica oleracea ('Hak') leaves (69.9 micrograms/kg), and the traditional tea 'Kehwa' (9.2 micrograms/kg). The highest level of NTCA was formed in smoked fish (3294 micrograms/kg). 'Salted tea' prepared according to local method formed considerable amounts of NPRO (360 micrograms/kg) and NPIC (5870 micrograms/kg) along with 3 yet unidentified non-volatile N-nitroso compounds. High values of 4315 micrograms/kg NPIC were also obtained following nitrosation of red chillies and mixed spice cake ('Wur') under simulated gastric conditions. These results suggest the possibility of an appreciable endogenous formation of N-nitroso compounds from local foods in Kashmir.

Food↗
PubMed1977

Tissue lipid responses to 3-hydroxy-3-methylglutaric acid with different dietary fats.

Simultaneous administration of 3-hydroxy-3-methylglutaric acid (HMG) for 4 weeks to rats fed 20% saturated fats prevented rise of serum cholesterol, triglycerides, and phospholipids. Except phospholipids, other liver lipids were significantly decreased. HMG administration for 4 weeks along with atherogenic diet significantly decreased cholesterol and phospholipids of serum, liver, aorta, and heart. The phospholipids of epididymal fat and brain were also significantly lowered. The triglyceride levels in serum, liver, and epididymal fat were significantly decreased. The maximal hypolipidemic effect of HMG was observed in serum.

Adipose Tissue↗
PubMed1977

Serum and liver lipid responses to 3-hydroxy-3-methylglutaric acid in rats on different carbohydrate diets.

Groups of male adult albino rats were administered 3-hydroxy-3-methylglutaric acid (HMG) intraperitoneally along with six diets differing only in the type of carbohydrate used. Groups not treated with HMG served as controls. HMG showed a significant cholesterol- and tri-glyceride-lowering effect in the whole serum, serum beta-lipoproteins, and liver of animals on all types of dietary carbohydrates. The effect was more marked in glucose, fructose, sucrose, and lactose. The phospholipid levels in whole serum, serum beta-lipoproteins, as well as in liver were also significantly lowered on all types of carbohydrates except dextrin and starch fed animals, where it had no effect on liver levels. The lipid-lowering effect of HMG seems to be independent of the type of carbohydrate in diet.

Animals↗
PubMed1976

3-Hydroxy-3-methylglutaric acid and triton-induced hyperlipidemia in rats.

3-Hydroxy-3-methylglutaric acid (HMG) significantly decreased cholesterol, triglyceride and phospholipid levels in whole serum, serum beta-lipoproteins and liver of Triton-induced hyperlipidemic rats. Therapeutically 50 mg HMG/kg is equivalent to 200 mg nicotinic acid/kg in lowering all these lipid parameters. HMG may exert its hypolipidemic effect through inhibition of lipoprotein synthesis.

Animals↗
PubMed1976

3-hydroxy-3-methylglutaric acid and experimental atherosclerosis in rats.

In rats 3-hydroxy-3-methylglutaric acid effectively counteracts the lipemic and atherosclerotic response of massive doses of vitamin D2. It regressed the formation of atheromatous arterial lesions. Furthermore the significant decrease in serum beta-lipoprotein levels on HMG treatment could be due to decrease in VLDL triglyceride and cholesterol levels.

Animals↗
PubMed1976

Protective effects of 3-hydroxy-3-methylglutaric acid in alcohol-induced lipemia.

Oral administration of l g of 3-hydroxy-3-methylglutaric acid (HMG) before the ingestion of whiskey and a fatty meal markedly reduced the elevation of serum triglycerides, beta-lipoproteins, phospholipids, and cholesterol in man. In rats receiving an ethanol and corn oil mixture, HMG also inhibited the increase in postprandial serum and liver lipids. A comparative study of HMG and nicotinic acid in rats showed that, therapeutically, 50 mg MHG/kg body weitht is equivalent to 200 mg nicotinic acid/kg body weight in offering almost total protection against lipemic effects of ethanol.

Adult↗
PubMed1975

Studies on the uptake of 2-deoxy-d-glucose in normal and malignant rat epithelial liver cells in culture.

The rate of uptake of 2-deoxyglucose in normal rat hepatic cells and chemically induced hepatoma cells in culture was studied. The hepatoma cells possessed a higher permeability to the sugar at all stages of culture. However, a decrease in the uptake of 2-deoxyglucose at confluency was observed in cells which exhibited density-dependent inhibition of growth, whether normal or malignant. The normal cells in mitosis showed an increased permeability to the sugar, whereas no such change was observed in the hepatoma cells. The kinetic studies of 2-deoxyglucose transport in normal and transformed rat liver showed a positive correlation between the increase in Vmax and the transformed state of the cells, whether they were transformed in vitro or in vivo. No changes in the apparent Km were found, indicating that there are no qualitative changes in the transport sites. The results suggest that an increase in the number of sites involved in glucose transport is a characteristic of chemically transformed rat liver epithelial cells.

Animals↗
PubMed1973

Bacterial metabolism of 3-hydroxy-3-methylglutaric acid.

An organism belonging to Pseudomonadaceae and capable of utilizing 3-hydroxy-3-methylglutarate as sole carbon source has been isolated from soil. Whole-cell preparations catalyze the oxidation of acetoacetate, acetate, glyoxylate, and citric acid cycle intermediates. Cell-free extracts of 3-hydroxy-3-methylglutarate-grown cells show an adenosine triphosphate, coenzyme A (CoA), and Mg(2+)-dependent conversion of 3-hydroxy-3-methylglutarate to 3-hydroxy-3-methylglutaryl-CoA. Succinyl-CoA-generating system has no effect on the activation and catabolism of 3-hydroxy-3-methylglutarate.

Acetates↗